The art of printing images with micro-fluid technology is relatively well known. A permanent or semi-permanent ejection head has access to a local or remote supply of fluid. The fluid ejects from an ejection zone to a print media in a pattern of pixels corresponding to images being printed. Over time, the fluid drops ejected from heads have become increasingly smaller to increase print resolution. Multiple ejection chips joined together are also known to make lengthy arrays, such as in page-wide printheads.
In lengthy arrays, fluid ejections near boundaries of adjacent chips have been known to cause problems of image “stitching.” Registration needs to occur between fluid drops from adjacent firing elements, but getting them stitched together is difficult especially when the firing elements reside on different substrates. Also, stitching challenges increase as arrays grow into page-wide dimensions, or larger, since print quality improves as the print zone narrows in width. Some prior art designs with narrow print zones have introduced firing elements for colors shifted laterally by one fluid via to align lengthwise with a different color near terminal ends of their respective chips. This, however, complicates chip fabrication. In other designs, complex chip shapes have been observed. This too complicates fabrication.
In still other designs, narrow print zones have tended to favor narrow ejection chips. Between colors, however, narrow chips leave little room to effectively seal off colors from adjacent colors. Narrow chips also have poor mechanical strength, which can cause elevated failure rates during subsequent assembly processes. They also leave limited space for distribution of power, signal and other routing of lines. Spacing distances between encapsulation materials, locations of bond pads on the chips and metallization lines connecting to bond pads represent still other concerns implicating efficient chip layout.
Accordingly, a need exists to significantly improve conventional ejection chip designs for larger stitched arrays. The need extends not only to improving stitching, but to manufacturing. Additional benefits and alternatives are also sought when devising solutions.